1. Field of the Invention
This invention relates generally to tack welding clamps, and more particularly to a removable two-ring clamp having a first segmented ring that is received on and secured around an end portion of a first tubular section and a second segmented ring that is received on and secured around an end portion of a second tubular section wherein the rings, when loosened, pivot relative to one another and also allow the tubular sections to be rotated relative to one another to accommodate positioning the axes of the sections in any combination of planes, and when tightened, firmly hold the two tubular sections concentrically end-to-end in the proper position while a small tack weld or bonding agent is placed at their joined ends.
2. Background Art
Many industries require the welding of sections of round tubing or pipe end-to-end to form complex shaped tubular assemblies; such as for example, refinery piping layouts, piping layouts in ships, submarines, aircraft, and spacecraft, civil engineering applications, sewer lines, exhaust systems for racing vehicles, and metal lines to carry exotic gases for silicon chip manufacturing to name a few. As used herein, the terms “tubular section” and tubular member” means one of several components of a tubular assembly.
Although there are many methods for holding tubular members and sections together for welding or bonding them together end-to-end, generally they apply to straight sections. The difficulty in attempting to hold the ends of curved or bent tubular members and pipes together, has been a longstanding problem for welders and pipe fitters, particularly when the sections are required to be concentric, axially aligned, and rotated in different planes relative to one another. Considerable time is spent determining the correct position and maintaining it while the sections are being welded or bonded. It is also challenging to ensure the concentricity between both tubular members. Bent metal tubular members have traditionally been “held in place” during welding through a variety of methods, such as temporarily using masking or metal tape around the facing sections, placing witness lines on the facing sections with a marker, and even super-gluing them if the bond only lasts for a few seconds.
There are several patents directed toward clamping devices of various construction designed to hold sections of round tubing or pipe end-to-end for welding or bonding them together end-to-end.
Fehlman, U.S. Pat. No. 3,422,519 discloses a portable lineup damp for alignment of abutting sections of pipe prior to welding. The lineup clamp includes first and second hingeably connected arcuate portions each comprising parallel arcuate members supported by longitudinal crossbars, and a plurality of longitudinal rollers supported by the pipe when the arcuate portions are circumferentially clamped about the pipe joint. A semi-circular segment extends across the members at the unhinged end of the first segment and faces outward therefrom and a sleeve extends across the members at the unhinged end of the second segment and includes a rotatable shaft therein, and a handle attached to the shaft. The free ends of a U-shaped yoke elements are pivotally attached to the ends of the sleeve off center therefrom, and the bight portion is received over and into the semicircular segment. Rotational movement of the handle causes the arcuate portions to clamp about the pipe joint and align the same for welding.
Arntz et al, U.S. Pat. No. 3,722,038 discloses a pipe-clamping device for positioning two pipe sections in axial alignment and with a desired axial end separation therebetween includes two sets of pipe-clamping shoes that are moved into positive clamping engagement with first and second pipe sections respectively by chains engaging those shoes and extending around respective ones of the pipe sections, the shoes have slotted plates for receiving selected links of the chains and terminal turnbuckle adjusting mechanisms on the chains being used to tighten them and to provide the positive clamping engagement. Radially disposed and adjustable pipe positioning or centering pins are provided on extensions of the first set of shoes for obtaining correct axial alignment of the second pipe section with the first pipe section. Removable turnbuckle mechanisms extend between the pipe-clamping shoes of one set and those of the other set to permit adjustment of the axial separation between the two pipe sections.
McFadden, U.S. Pat. No. 3,925,854 discloses an alignment clamp that holds a pair of pipe sections or structural shapes in alignment for welding and includes a band which is secured to a first pipe section, the band being larger in diameter than such first pipe section and spaced from the first pipe section. The band comprises two segments which are hingedly connected and adapted to be locked over the first pipe section. Mounted upon the band are pairs of lever dogs pivotally supported by the band. The dogs are rotated relative to the band to cause forward ends of the dogs to grasp a second pipe section in alignment with the first. The lever dogs extend outwardly from the second pipe section to provide a gap under the dogs between the pipe sections to permit welding therebetween.
Dearman, U.S. Pat. No. 3,944,202 discloses a clamping assembly for aligning abutting ends of pipe sections to form a mitered joint. A plurality of individual clamp assemblies are clamped in circumferentially spaced positions upon one pipe section by a circumferentially extending chain, each clamp assembly having an elongate jack arm which can be clamped in selected positions of circumferential and axial adjustment upon the one pipe section so that the jack arms may be projected to different axial distances from the chain into operative engagement with a second pipe section lying in a plane inclined to axis of the one pipe section.
Kagimoto, U.S. Pat. No. 4,750,662 discloses a pipe clamping and alignment tool for locating and clamping pipe sections in end to end alignment for welding which includes a pair of clamping assemblies for the respective pipe sections threaded respectively on opposite-hand threads of a turnbuckle-type bolt. Each clamping assembly has a cradle for receiving the respective pipe section, a releasable U-bolt clamp for holding the pipe section on the cradle, and pairs of angled adjusting screws for engaging the pipe section and adjusting its alignment both longitudinally and laterally.
Poncelet, U.S. Pat. No. 5,165,160 discloses an apparatus and method for aligning conduits including pipes, pipe fittings and the like prior to joining. The apparatus includes a first ring assembly for removably encircling an end portion of a first conduit to be joined and a second ring assembly for removably encircling an end portion of a second conduit to be joined to the end portion of the first conduit. Circumferentially spaced bridge members extend between the first and second ring assemblies connecting them together axially spaced apart sufficiently to permit joining of the end portions of the conduits between the first and second ring assemblies. First and second screws on each bridge member move the first and second conduits into an axially aligned position. lly aligning the end portions of the first and second conduits, the aligning provisions being disposed between the ring members and including a plurality of adjustable contact surfaces for contacting respective end portions of the first and second conduits. The contact surfaces are moveable relative to each other to move the first and second conduits into an axially aligned position.
Collie. U.S. Pat. No. 6,325,277 discloses an apparatus and method for precisely aligning and holding first and second thin walled stainless steel sanitary tubing segments end-to-end to allow for tack welding of the segments together during a tube assembly process. The apparatus includes first and second pivotally connected C-shaped clamp halves that contact almost an entire circumferential path along the outer walls of both aligned tubing segments, each having first and second clamp portions separated by a cutout large enough to permit tack fusion welding at the seam, and a continuous inner surface contacting a respective portion of the tubing segments. A locking rod connecting the first and second clamp parts holds them in position about the ends of the first and second tubing segments. A threaded shaft is pivotally and slidably mounted on the rod and extends through a bracket to further connect the clamp portions, and a nut is threadedly received on the shaft. An elongated pin extends through the bore of the nut to permit sliding movement therein.
Shelton, U.S. Pat. No. 6,990,712 discloses a pipe joining tool which includes a mounting bracket for releasable attachment to a pipe. The mounting bracket has a U-shaped platform with an intermediate portion for engaging a pipe and a pair of slotted end portions extending from the opposite ends of the intermediate portion in a substantially parallel manner. A wedge slidably extends through the slots in the end portions for driving a pipe positioned within the U-shaped platform into tight engagement with the intermediate portion. A flexible link is secured to the mounting bracket and extends therefrom. A pipe fitting keeper is carried by the flexible link for releasably grasping a pipe fitting and suspending the pipe fitting adjacent the end of a pipe positioned within the U-shaped platform. A pair of spaced apart legs projects forwardly from the intermediate portion of the U-shaped platform. Each of the spaced apart legs has an internally threaded bore within which is positioned a bolt. Selective rotation of each bolt moves the pipe fitting suspended by the pipe fitting keeper into alignment with the end of a pipe positioned within the U-shaped platform.